If your using Plato the correct answer is (A. It accepts protons)
In a covalent bond, the atoms bond by sharing electrons. Covalent bonds usually occur between nonmetals. For example, in water (H2O) each hydrogen (H) and oxygen (O) share a pair of electrons to make a molecule of two hydrogen atoms single bonded to a single oxygen atom.
The two first ones because it’s always the opposite
A covalent bond is your answer